Slat roofs having rotatable slats are usually used to cover an outdoor area, such as a terrace covering or veranda roof, etc. In addition to said slats, a slat roof of this type may also comprise one or more additional slats. Using such a rotatably arranged slat shaft, the slats are rotatable between an open position, in which an intermediate space extends between the slats, and a closed position, in which the slats together form a closed shelter. By rotating the slats between these positions, it is possible to regulate the incidence of light, the radiant heat and the ventilation into the space underneath the slats. By directing the slats, it is possible to protect against the sun and/or wind or, on the contrary, to let them in.
In addition, the slats may optionally be provided slideably in the slat roof, with, in that case, the slats being typically slideable between a position in which they are spread out over the slat roof and a position in which they are substantially arranged at one side of the slat roof.
A problem with such slat roofs is that the beams begin to bulge under the weight and the bending of the slats suspended between them in the plane of these slats. Given the growing trend of designing larger uninterrupted covers to have such slat roofs and of using heavier slats in such covers, such as glass slats, for example, this is an ever increasing problem.
In order to remedy this problem, the beams are often designed to be sturdier. However, this requires more material and means that the beams become a great deal more expensive, which also results in a considerable increase in the cost price of the entire slat roof. Wider and heavier beams are often also undesirable for aesthetic reasons.
It is also known to place the beams at an incline, counter to the bulging, so that they return to being upright as a result of the bulging. However, it is difficult to connect such beams to other girders which in this case together form a frame for the slat roof. Such beams are difficult to mitre in an aesthetic manner.
It is further known to provide a transverse girder in the centre of such a slat roof. However, most customers do not wish for such a division of their slat roof using such a transverse girder.